"Guideline 3.2 - Business
During our review, we found that your app was designed specifically for a single or small number of businesses or organizations, including their partners, clients, or employees. However, the salable storefronts you selected in App Store Connect are not limited to the location(s) of your app's intended audience.
Business apps with limited audiences should generally be distributed using Apple Business Manager. Since Apple Business Manager is not currently available where your app needs to be distributed, you can distribute your app on the App Store if your storefronts are appropriately restricted.
To resolve this issue, please change your app's availability to not to include the China storefront for intended audience.